"He is all over the pitch, he covers a lot of ground and recovers a lot of balls. He is Bayern's lungs. As many of his teammates and manager have said, he is the piece that the team needed."

The clash with Bayern will be a record sixth consecutive semi-final for Barca, but having lost at this stage in three of the previous five years, Busquets is aware of how fine the margins are at this stage of the competition.

"It is a very even tie between two great teams that play great football. The team that is better prepared, more concentrated, is the one that will get to the final.

"Small details or an error will tip the balance. We hope it will be in our favour."

Martinez though was just as effusive about the role played by Busquets in Barca's system.

"Sergio Busquets is the key piece at Barca. There are others who capture the headlines more, but that Barca has achieved so many it is thanks to him," he also told Barca's website.

"He always maintains his position. He gives life to the rest of the players, like Xavi or (Andres) Iniesta, who can incorporate themselves into the attack with their back well-covered."

Bayern's form of late at both domestic and European level has been sensational and having taken commanding leads in the first-legs of their knockout ties against Arsenal and Juventus in previous rounds, Martinez believes it is vital to make home advantage count on Tuesday.

"I think it is the ideal moment for us to face Barca. We are in great form, in the Bundesliga and in the other competitions, the problem is that they too are in good form.

"With Arsenal and Juventus we went into the return-leg with a considerable advantage. Now we play the first-leg at the Allianz and we need to obtain a good result because over there we will suffer a lot."